The invention relates to fluted filter media coating, winding, finishing and manufacturing systems for filters including various fluid filters including air filters and including high temperature filters such as diesel exhaust aftertreatment filters.
The invention arose during continuing development efforts relating to air filters and to diesel exhaust aftertreatment filters. Various improved coating, winding, finishing and manufacturing apparatus, methods and systems have been developed, including: an improved coating system for applying adhesive to flute tips of a fluted filter media sheet including pleated filter media and corrugated filter media; an improved spiral-winding system for winding first and second sheets of filter media into a spiral-wound roll, the first sheet having a plurality of flutes defined by wall segments extending in zig-zag manner between flute tips at axially extending flute bend lines, the flute tips on one side of the first sheet being in contiguous relation with and adhesively bonded to the second sheet to define axial flow channels; an improved finishing system, including a tensioning system, for increasing and maintaining wound-in tension in the spiral-wound roll, including improvements minimizing axial separation of layers in the spiral-wound roll; an improved overall manufacturing process incorporating the noted systems in combination; and a cost effective manufacturing system for making plural spiral-wound filters.